1/* 2 * auth.c - PPP authentication and phase control. 3 * 4 * Copyright (c) 1993-2002 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. The name(s) of the authors of this software must not be used to 14 * endorse or promote products derived from this software without 15 * prior written permission. 16 * 17 * 3. Redistributions of any form whatsoever must retain the following 18 * acknowledgment: 19 * "This product includes software developed by Paul Mackerras 20 * <paulus@samba.org>". 21 * 22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 29 * 30 * Derived from main.c, which is: 31 * 32 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved. 33 * 34 * Redistribution and use in source and binary forms, with or without 35 * modification, are permitted provided that the following conditions 36 * are met: 37 * 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in 43 * the documentation and/or other materials provided with the 44 * distribution. 45 * 46 * 3. The name "Carnegie Mellon University" must not be used to 47 * endorse or promote products derived from this software without 48 * prior written permission. For permission or any legal 49 * details, please contact 50 * Office of Technology Transfer 51 * Carnegie Mellon University 52 * 5000 Forbes Avenue 53 * Pittsburgh, PA 15213-3890 54 * (412) 268-4387, fax: (412) 268-7395 55 * tech-transfer@andrew.cmu.edu 56 * 57 * 4. Redistributions of any form whatsoever must retain the following 58 * acknowledgment: 59 * "This product includes software developed by Computing Services 60 * at Carnegie Mellon University (http://www.cmu.edu/computing/)." 61 * 62 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO 63 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 64 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE 65 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 66 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 67 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 68 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 69 */ 70 71#define RCSID "$Id: auth.c,v 1.101 2004/11/12 10:30:51 paulus Exp $" 72 73#include <stdio.h> 74#include <stddef.h> 75#include <stdlib.h> 76#include <unistd.h> 77#include <errno.h> 78#include <pwd.h> 79#include <grp.h> 80#include <string.h> 81#include <sys/types.h> 82#include <sys/stat.h> 83#include <sys/socket.h> 84#include <utmp.h> 85#include <fcntl.h> 86#if defined(_PATH_LASTLOG) && defined(__linux__) 87#include <lastlog.h> 88#endif 89 90#include <netdb.h> 91#include <netinet/in.h> 92#include <arpa/inet.h> 93 94#ifdef USE_PAM 95#include <security/pam_appl.h> 96#endif 97 98#ifdef HAS_SHADOW 99#include <shadow.h> 100#ifndef PW_PPP 101#define PW_PPP PW_LOGIN 102#endif 103#endif 104#include <time.h> 105 106#include "pppd.h" 107#include "fsm.h" 108#include "lcp.h" 109#include "ccp.h" 110#include "ecp.h" 111#include "ipcp.h" 112#include "upap.h" 113#include "chap-new.h" 114#include "eap.h" 115#ifdef CBCP_SUPPORT 116#include "cbcp.h" 117#endif 118#include "pathnames.h" 119 120static const char rcsid[] = RCSID; 121 122/* Bits in scan_authfile return value */ 123#define NONWILD_SERVER 1 124#define NONWILD_CLIENT 2 125 126#define ISWILD(word) (word[0] == '*' && word[1] == 0) 127 128/* The name by which the peer authenticated itself to us. */ 129char peer_authname[MAXNAMELEN]; 130 131/* Records which authentication operations haven't completed yet. */ 132static int auth_pending[NUM_PPP]; 133 134/* Records which authentication operations have been completed. */ 135int auth_done[NUM_PPP]; 136 137/* Set if we have successfully called plogin() */ 138static int logged_in; 139 140/* List of addresses which the peer may use. */ 141static struct permitted_ip *addresses[NUM_PPP]; 142 143/* Wordlist giving addresses which the peer may use 144 without authenticating itself. */ 145static struct wordlist *noauth_addrs; 146 147/* Remote telephone number, if available */ 148char remote_number[MAXNAMELEN]; 149 150/* Wordlist giving remote telephone numbers which may connect. */ 151static struct wordlist *permitted_numbers; 152 153/* Extra options to apply, from the secrets file entry for the peer. */ 154static struct wordlist *extra_options; 155 156/* Number of network protocols which we have opened. */ 157static int num_np_open; 158 159/* Number of network protocols which have come up. */ 160static int num_np_up; 161 162/* Set if we got the contents of passwd[] from the pap-secrets file. */ 163static int passwd_from_file; 164 165/* Set if we require authentication only because we have a default route. */ 166static bool default_auth; 167 168/* Hook to enable a plugin to control the idle time limit */ 169int (*idle_time_hook) __P((struct ppp_idle *)) = NULL; 170 171/* Hook for a plugin to say whether we can possibly authenticate any peer */ 172int (*pap_check_hook) __P((void)) = NULL; 173 174/* Hook for a plugin to check the PAP user and password */ 175int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp, 176 struct wordlist **paddrs, 177 struct wordlist **popts)) = NULL; 178 179/* Hook for a plugin to know about the PAP user logout */ 180void (*pap_logout_hook) __P((void)) = NULL; 181 182/* Hook for a plugin to get the PAP password for authenticating us */ 183int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL; 184 185/* Hook for a plugin to say if we can possibly authenticate a peer using CHAP */ 186int (*chap_check_hook) __P((void)) = NULL; 187 188/* Hook for a plugin to get the CHAP password for authenticating us */ 189int (*chap_passwd_hook) __P((char *user, char *passwd)) = NULL; 190 191/* Hook for a plugin to say whether it is OK if the peer 192 refuses to authenticate. */ 193int (*null_auth_hook) __P((struct wordlist **paddrs, 194 struct wordlist **popts)) = NULL; 195 196int (*allowed_address_hook) __P((u_int32_t addr)) = NULL; 197 198/* A notifier for when the peer has authenticated itself, 199 and we are proceeding to the network phase. */ 200struct notifier *auth_up_notifier = NULL; 201 202/* A notifier for when the link goes down. */ 203struct notifier *link_down_notifier = NULL; 204 205/* 206 * This is used to ensure that we don't start an auth-up/down 207 * script while one is already running. 208 */ 209enum script_state { 210 s_down, 211 s_up 212}; 213 214static enum script_state auth_state = s_down; 215static enum script_state auth_script_state = s_down; 216static pid_t auth_script_pid = 0; 217 218static int used_login; /* peer authenticated against login database */ 219 220/* 221 * Option variables. 222 */ 223bool uselogin = 0; /* Use /etc/passwd for checking PAP */ 224bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */ 225bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */ 226bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */ 227bool refuse_eap = 0; /* Don't wanna auth. ourselves with EAP */ 228#ifdef CHAPMS 229bool refuse_mschap = 0; /* Don't wanna auth. ourselves with MS-CHAP */ 230bool refuse_mschap_v2 = 0; /* Don't wanna auth. ourselves with MS-CHAPv2 */ 231#else 232bool refuse_mschap = 1; /* Don't wanna auth. ourselves with MS-CHAP */ 233bool refuse_mschap_v2 = 1; /* Don't wanna auth. ourselves with MS-CHAPv2 */ 234#endif 235bool usehostname = 0; /* Use hostname for our_name */ 236bool auth_required = 0; /* Always require authentication from peer */ 237bool allow_any_ip = 0; /* Allow peer to use any IP address */ 238bool explicit_remote = 0; /* User specified explicit remote name */ 239char remote_name[MAXNAMELEN]; /* Peer's name for authentication */ 240 241static char *uafname; /* name of most recent +ua file */ 242 243extern char *crypt __P((const char *, const char *)); 244 245/* Prototypes for procedures local to this file. */ 246 247static void network_phase __P((int)); 248static void check_idle __P((void *)); 249static void connect_time_expired __P((void *)); 250static int plogin __P((char *, char *, char **)); 251static void plogout __P((void)); 252static int null_login __P((int)); 253static int get_pap_passwd __P((char *)); 254static int have_pap_secret __P((int *)); 255static int have_chap_secret __P((char *, char *, int, int *)); 256static int have_srp_secret __P((char *client, char *server, int need_ip, 257 int *lacks_ipp)); 258static int ip_addr_check __P((u_int32_t, struct permitted_ip *)); 259static int scan_authfile __P((FILE *, char *, char *, char *, 260 struct wordlist **, struct wordlist **, 261 char *, int)); 262static void free_wordlist __P((struct wordlist *)); 263static void auth_script __P((char *)); 264static void auth_script_done __P((void *)); 265static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *)); 266static int some_ip_ok __P((struct wordlist *)); 267static int setupapfile __P((char **)); 268static int privgroup __P((char **)); 269static int set_noauth_addr __P((char **)); 270static int set_permitted_number __P((char **)); 271static void check_access __P((FILE *, char *)); 272static int wordlist_count __P((struct wordlist *)); 273 274#ifdef MAXOCTETS 275static void check_maxoctets __P((void *)); 276#endif 277 278/* 279 * Authentication-related options. 280 */ 281option_t auth_options[] = { 282 { "auth", o_bool, &auth_required, 283 "Require authentication from peer", OPT_PRIO | 1 }, 284 { "noauth", o_bool, &auth_required, 285 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV, 286 &allow_any_ip }, 287 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap, 288 "Require PAP authentication from peer", 289 OPT_PRIOSUB | 1, &auth_required }, 290 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap, 291 "Require PAP authentication from peer", 292 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required }, 293 { "require-chap", o_bool, &auth_required, 294 "Require CHAP authentication from peer", 295 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5, 296 &lcp_wantoptions[0].chap_mdtype }, 297 { "+chap", o_bool, &auth_required, 298 "Require CHAP authentication from peer", 299 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5, 300 &lcp_wantoptions[0].chap_mdtype }, 301#ifdef CHAPMS 302 { "require-mschap", o_bool, &auth_required, 303 "Require MS-CHAP authentication from peer", 304 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT, 305 &lcp_wantoptions[0].chap_mdtype }, 306 { "+mschap", o_bool, &auth_required, 307 "Require MS-CHAP authentication from peer", 308 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT, 309 &lcp_wantoptions[0].chap_mdtype }, 310 { "require-mschap-v2", o_bool, &auth_required, 311 "Require MS-CHAPv2 authentication from peer", 312 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2, 313 &lcp_wantoptions[0].chap_mdtype }, 314 { "+mschap-v2", o_bool, &auth_required, 315 "Require MS-CHAPv2 authentication from peer", 316 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2, 317 &lcp_wantoptions[0].chap_mdtype }, 318#endif 319 320 { "refuse-pap", o_bool, &refuse_pap, 321 "Don't agree to auth to peer with PAP", 1 }, 322 { "-pap", o_bool, &refuse_pap, 323 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 }, 324 { "refuse-chap", o_bool, &refuse_chap, 325 "Don't agree to auth to peer with CHAP", 326 OPT_A2CLRB | MDTYPE_MD5, 327 &lcp_allowoptions[0].chap_mdtype }, 328 { "-chap", o_bool, &refuse_chap, 329 "Don't allow CHAP authentication with peer", 330 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5, 331 &lcp_allowoptions[0].chap_mdtype }, 332#ifdef CHAPMS 333 { "refuse-mschap", o_bool, &refuse_mschap, 334 "Don't agree to auth to peer with MS-CHAP", 335 OPT_A2CLRB | MDTYPE_MICROSOFT, 336 &lcp_allowoptions[0].chap_mdtype }, 337 { "-mschap", o_bool, &refuse_mschap, 338 "Don't allow MS-CHAP authentication with peer", 339 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT, 340 &lcp_allowoptions[0].chap_mdtype }, 341 { "refuse-mschap-v2", o_bool, &refuse_mschap_v2, 342 "Don't agree to auth to peer with MS-CHAPv2", 343 OPT_A2CLRB | MDTYPE_MICROSOFT_V2, 344 &lcp_allowoptions[0].chap_mdtype }, 345 { "-mschap-v2", o_bool, &refuse_mschap_v2, 346 "Don't allow MS-CHAPv2 authentication with peer", 347 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2, 348 &lcp_allowoptions[0].chap_mdtype }, 349#endif 350 351 { "require-eap", o_bool, &lcp_wantoptions[0].neg_eap, 352 "Require EAP authentication from peer", OPT_PRIOSUB | 1, 353 &auth_required }, 354 { "refuse-eap", o_bool, &refuse_eap, 355 "Don't agree to authenticate to peer with EAP", 1 }, 356 357 { "name", o_string, our_name, 358 "Set local name for authentication", 359 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN }, 360 361 { "+ua", o_special, (void *)setupapfile, 362 "Get PAP user and password from file", 363 OPT_PRIO | OPT_A2STRVAL, &uafname }, 364 365 { "user", o_string, user, 366 "Set name for auth with peer", OPT_PRIO | OPT_STATIC, NULL, MAXNAMELEN }, 367 368 { "password", o_string, passwd, 369 "Password for authenticating us to the peer", 370 OPT_PRIO | OPT_STATIC | OPT_HIDE, NULL, MAXSECRETLEN }, 371 372 { "usehostname", o_bool, &usehostname, 373 "Must use hostname for authentication", 1 }, 374 375 { "remotename", o_string, remote_name, 376 "Set remote name for authentication", OPT_PRIO | OPT_STATIC, 377 &explicit_remote, MAXNAMELEN }, 378 379 { "login", o_bool, &uselogin, 380 "Use system password database for PAP", 1 }, 381 382 { "papcrypt", o_bool, &cryptpap, 383 "PAP passwords are encrypted", 1 }, 384 385 { "privgroup", o_special, (void *)privgroup, 386 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST }, 387 388 { "allow-ip", o_special, (void *)set_noauth_addr, 389 "Set IP address(es) which can be used without authentication", 390 OPT_PRIV | OPT_A2LIST }, 391 392 { "remotenumber", o_string, remote_number, 393 "Set remote telephone number for authentication", OPT_PRIO | OPT_STATIC, 394 NULL, MAXNAMELEN }, 395 396 { "allow-number", o_special, (void *)set_permitted_number, 397 "Set telephone number(s) which are allowed to connect", 398 OPT_PRIV | OPT_A2LIST }, 399 400 { NULL } 401}; 402 403/* 404 * setupapfile - specifies UPAP info for authenticating with peer. 405 */ 406static int 407setupapfile(argv) 408 char **argv; 409{ 410 FILE *ufile; 411 int l; 412 char u[MAXNAMELEN], p[MAXSECRETLEN]; 413 char *fname; 414 415 lcp_allowoptions[0].neg_upap = 1; 416 417 /* open user info file */ 418 fname = strdup(*argv); 419 if (fname == NULL) 420 novm("+ua file name"); 421 seteuid(getuid()); 422 ufile = fopen(fname, "r"); 423 seteuid(0); 424 if (ufile == NULL) { 425 option_error("unable to open user login data file %s", fname); 426 return 0; 427 } 428 check_access(ufile, fname); 429 uafname = fname; 430 431 /* get username */ 432 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL 433 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL) { 434 fclose(ufile); 435 option_error("unable to read user login data file %s", fname); 436 return 0; 437 } 438 fclose(ufile); 439 440 /* get rid of newlines */ 441 l = strlen(u); 442 if (l > 0 && u[l-1] == '\n') 443 u[l-1] = 0; 444 l = strlen(p); 445 if (l > 0 && p[l-1] == '\n') 446 p[l-1] = 0; 447 448 if (override_value("user", option_priority, fname)) 449 strlcpy(user, u, sizeof(user)); 450 if (override_value("passwd", option_priority, fname)) 451 strlcpy(passwd, p, sizeof(passwd)); 452 453 return (1); 454} 455 456 457/* 458 * privgroup - allow members of the group to have privileged access. 459 */ 460static int 461privgroup(argv) 462 char **argv; 463{ 464 struct group *g; 465 int i; 466 467 g = getgrnam(*argv); 468 if (g == 0) { 469 option_error("group %s is unknown", *argv); 470 return 0; 471 } 472 for (i = 0; i < ngroups; ++i) { 473 if (groups[i] == g->gr_gid) { 474 privileged = 1; 475 break; 476 } 477 } 478 return 1; 479} 480 481 482/* 483 * set_noauth_addr - set address(es) that can be used without authentication. 484 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets. 485 */ 486static int 487set_noauth_addr(argv) 488 char **argv; 489{ 490 char *addr = *argv; 491 int l = strlen(addr) + 1; 492 struct wordlist *wp; 493 494 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l); 495 if (wp == NULL) 496 novm("allow-ip argument"); 497 wp->word = (char *) (wp + 1); 498 wp->next = noauth_addrs; 499 BCOPY(addr, wp->word, l); 500 noauth_addrs = wp; 501 return 1; 502} 503 504 505/* 506 * set_permitted_number - set remote telephone number(s) that may connect. 507 */ 508static int 509set_permitted_number(argv) 510 char **argv; 511{ 512 char *number = *argv; 513 int l = strlen(number) + 1; 514 struct wordlist *wp; 515 516 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l); 517 if (wp == NULL) 518 novm("allow-number argument"); 519 wp->word = (char *) (wp + 1); 520 wp->next = permitted_numbers; 521 BCOPY(number, wp->word, l); 522 permitted_numbers = wp; 523 return 1; 524} 525 526 527/* 528 * An Open on LCP has requested a change from Dead to Establish phase. 529 * Do what's necessary to bring the physical layer up. 530 */ 531void 532link_required(unit) 533 int unit; 534{ 535 new_phase(PHASE_SERIALCONN); 536 537 devfd = the_channel->connect(); 538 if (devfd < 0) 539 goto fail; 540 541 /* set up the serial device as a ppp interface */ 542 /* 543 * N.B. we used to do tdb_writelock/tdb_writeunlock around this 544 * (from establish_ppp to set_ifunit). However, we won't be 545 * doing the set_ifunit in multilink mode, which is the only time 546 * we need the atomicity that the tdb_writelock/tdb_writeunlock 547 * gives us. Thus we don't need the tdb_writelock/tdb_writeunlock. 548 */ 549 fd_ppp = the_channel->establish_ppp(devfd); 550 if (fd_ppp < 0) { 551 status = EXIT_FATAL_ERROR; 552 goto disconnect; 553 } 554 555 if (!demand && ifunit >= 0) 556 set_ifunit(1); 557 558 /* 559 * Start opening the connection and wait for 560 * incoming events (reply, timeout, etc.). 561 */ 562 if (ifunit >= 0) 563 notice("Connect: %s <--> %s", ifname, ppp_devnam); 564 else 565 notice("Starting negotiation on %s", ppp_devnam); 566 add_fd(fd_ppp); 567 568 status = EXIT_NEGOTIATION_FAILED; 569 new_phase(PHASE_ESTABLISH); 570 571 lcp_lowerup(0); 572 return; 573 574 disconnect: 575 new_phase(PHASE_DISCONNECT); 576 if (the_channel->disconnect) 577 the_channel->disconnect(); 578 579 fail: 580 new_phase(PHASE_DEAD); 581 if (the_channel->cleanup) 582 (*the_channel->cleanup)(); 583 584} 585 586/* 587 * LCP has terminated the link; go to the Dead phase and take the 588 * physical layer down. 589 */ 590void 591link_terminated(unit) 592 int unit; 593{ 594 if (phase == PHASE_DEAD || phase == PHASE_MASTER) 595 return; 596 new_phase(PHASE_DISCONNECT); 597 598 if (pap_logout_hook) { 599 pap_logout_hook(); 600 } else { 601 if (logged_in) 602 plogout(); 603 } 604 605 if (!doing_multilink) { 606 notice("Connection terminated."); 607 print_link_stats(); 608 } else 609 notice("Link terminated."); 610 611 /* 612 * Delete pid files before disestablishing ppp. Otherwise it 613 * can happen that another pppd gets the same unit and then 614 * we delete its pid file. 615 */ 616 if (!doing_multilink && !demand) 617 remove_pidfiles(); 618 619 /* 620 * If we may want to bring the link up again, transfer 621 * the ppp unit back to the loopback. Set the 622 * real serial device back to its normal mode of operation. 623 */ 624 if (fd_ppp >= 0) { 625 remove_fd(fd_ppp); 626 clean_check(); 627 the_channel->disestablish_ppp(devfd); 628 if (doing_multilink) 629 mp_exit_bundle(); 630 fd_ppp = -1; 631 } 632 if (!hungup) 633 lcp_lowerdown(0); 634 if (!doing_multilink && !demand) 635 script_unsetenv("IFNAME"); 636 637 /* 638 * Run disconnector script, if requested. 639 * XXX we may not be able to do this if the line has hung up! 640 */ 641 if (devfd >= 0 && the_channel->disconnect) { 642 the_channel->disconnect(); 643 devfd = -1; 644 } 645 646 if (doing_multilink && multilink_master) { 647 if (!bundle_terminating) 648 new_phase(PHASE_MASTER); 649 else 650 mp_bundle_terminated(); 651 } else 652 new_phase(PHASE_DEAD); 653} 654 655/* 656 * LCP has gone down; it will either die or try to re-establish. 657 */ 658void 659link_down(unit) 660 int unit; 661{ 662 if (auth_state != s_down) { 663 notify(link_down_notifier, 0); 664 auth_state = s_down; 665 if (auth_script_state == s_up && auth_script_pid == 0) { 666 update_link_stats(unit); 667 auth_script_state = s_down; 668 auth_script(_PATH_AUTHDOWN); 669 } 670 } 671 if (!doing_multilink) { 672 upper_layers_down(unit); 673 if (phase != PHASE_DEAD && phase != PHASE_MASTER) 674 new_phase(PHASE_ESTABLISH); 675 } 676 /* XXX if doing_multilink, should do something to stop 677 network-layer traffic on the link */ 678} 679 680void upper_layers_down(int unit) 681{ 682 int i; 683 struct protent *protp; 684 685 for (i = 0; (protp = protocols[i]) != NULL; ++i) { 686 if (!protp->enabled_flag) 687 continue; 688 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL) 689 (*protp->lowerdown)(unit); 690 if (protp->protocol < 0xC000 && protp->close != NULL) 691 (*protp->close)(unit, "LCP down"); 692 } 693 num_np_open = 0; 694 num_np_up = 0; 695} 696 697/* 698 * The link is established. 699 * Proceed to the Dead, Authenticate or Network phase as appropriate. 700 */ 701void 702link_established(unit) 703 int unit; 704{ 705 int auth; 706 lcp_options *wo = &lcp_wantoptions[unit]; 707 lcp_options *go = &lcp_gotoptions[unit]; 708 lcp_options *ho = &lcp_hisoptions[unit]; 709 int i; 710 struct protent *protp; 711 712 /* 713 * Tell higher-level protocols that LCP is up. 714 */ 715 if (!doing_multilink) { 716 for (i = 0; (protp = protocols[i]) != NULL; ++i) 717 if (protp->protocol != PPP_LCP && protp->enabled_flag 718 && protp->lowerup != NULL) 719 (*protp->lowerup)(unit); 720 } 721 722 if (!auth_required && noauth_addrs != NULL) 723 set_allowed_addrs(unit, NULL, NULL); 724 725 if (auth_required && !(go->neg_upap || go->neg_chap || go->neg_eap)) { 726 /* 727 * We wanted the peer to authenticate itself, and it refused: 728 * if we have some address(es) it can use without auth, fine, 729 * otherwise treat it as though it authenticated with PAP using 730 * a username of "" and a password of "". If that's not OK, 731 * boot it out. 732 */ 733 if (noauth_addrs != NULL) { 734 set_allowed_addrs(unit, NULL, NULL); 735 } else if (!wo->neg_upap || uselogin || !null_login(unit)) { 736 warn("peer refused to authenticate: terminating link"); 737 lcp_close(unit, "peer refused to authenticate"); 738 status = EXIT_PEER_AUTH_FAILED; 739 return; 740 } 741 } 742 743 new_phase(PHASE_AUTHENTICATE); 744 used_login = 0; 745 auth = 0; 746 if (go->neg_eap) { 747 eap_authpeer(unit, our_name); 748 auth |= EAP_PEER; 749 } else if (go->neg_chap) { 750 chap_auth_peer(unit, our_name, CHAP_DIGEST(go->chap_mdtype)); 751 auth |= CHAP_PEER; 752 } else if (go->neg_upap) { 753 upap_authpeer(unit); 754 auth |= PAP_PEER; 755 } 756 if (ho->neg_eap) { 757 eap_authwithpeer(unit, user); 758 auth |= EAP_WITHPEER; 759 } else if (ho->neg_chap) { 760 chap_auth_with_peer(unit, user, CHAP_DIGEST(ho->chap_mdtype)); 761 auth |= CHAP_WITHPEER; 762 } else if (ho->neg_upap) { 763 if (passwd[0] == 0) { 764 passwd_from_file = 1; 765 if (!get_pap_passwd(passwd)) 766 error("No secret found for PAP login"); 767 } 768 upap_authwithpeer(unit, user, passwd); 769 auth |= PAP_WITHPEER; 770 } 771 auth_pending[unit] = auth; 772 auth_done[unit] = 0; 773 774 if (!auth) 775 network_phase(unit); 776} 777 778/* 779 * Proceed to the network phase. 780 */ 781static void 782network_phase(unit) 783 int unit; 784{ 785 lcp_options *go = &lcp_gotoptions[unit]; 786 787 /* Log calling number. */ 788 if (*remote_number) 789 notice("peer from calling number %q authorized", remote_number); 790 791 /* 792 * If the peer had to authenticate, run the auth-up script now. 793 */ 794 if (go->neg_chap || go->neg_upap || go->neg_eap) { 795 notify(auth_up_notifier, 0); 796 auth_state = s_up; 797 if (auth_script_state == s_down && auth_script_pid == 0) { 798 auth_script_state = s_up; 799 auth_script(_PATH_AUTHUP); 800 } 801 } 802 803#ifdef CBCP_SUPPORT 804 /* 805 * If we negotiated callback, do it now. 806 */ 807 if (go->neg_cbcp) { 808 new_phase(PHASE_CALLBACK); 809 (*cbcp_protent.open)(unit); 810 return; 811 } 812#endif 813 814 /* 815 * Process extra options from the secrets file 816 */ 817 if (extra_options) { 818 options_from_list(extra_options, 1); 819 free_wordlist(extra_options); 820 extra_options = 0; 821 } 822 start_networks(unit); 823} 824 825void 826start_networks(unit) 827 int unit; 828{ 829 int i; 830 struct protent *protp; 831 int ecp_required, mppe_required; 832 833 new_phase(PHASE_NETWORK); 834 835#ifdef HAVE_MULTILINK 836 if (multilink) { 837 if (mp_join_bundle()) { 838 if (updetach && !nodetach) 839 detach(); 840 return; 841 } 842 } 843#endif /* HAVE_MULTILINK */ 844 845#ifdef PPP_FILTER 846 if (!demand) 847 set_filters(&pass_filter, &active_filter); 848#endif 849 /* Start CCP and ECP */ 850 for (i = 0; (protp = protocols[i]) != NULL; ++i) 851 if ((protp->protocol == PPP_ECP || protp->protocol == PPP_CCP) 852 && protp->enabled_flag && protp->open != NULL) 853 (*protp->open)(0); 854 855 /* 856 * Bring up other network protocols iff encryption is not required. 857 */ 858 ecp_required = ecp_gotoptions[unit].required; 859 mppe_required = ccp_gotoptions[unit].mppe; 860 if (!ecp_required && !mppe_required) 861 continue_networks(unit); 862} 863 864void 865continue_networks(unit) 866 int unit; 867{ 868 int i; 869 struct protent *protp; 870 871 /* 872 * Start the "real" network protocols. 873 */ 874 for (i = 0; (protp = protocols[i]) != NULL; ++i) 875 if (protp->protocol < 0xC000 876 && protp->protocol != PPP_CCP && protp->protocol != PPP_ECP 877 && protp->enabled_flag && protp->open != NULL) { 878 (*protp->open)(0); 879 ++num_np_open; 880 } 881 882 if (num_np_open == 0) 883 /* nothing to do */ 884 lcp_close(0, "No network protocols running"); 885} 886 887/* 888 * The peer has failed to authenticate himself using `protocol'. 889 */ 890void 891auth_peer_fail(unit, protocol) 892 int unit, protocol; 893{ 894 /* 895 * Authentication failure: take the link down 896 */ 897 lcp_close(unit, "Authentication failed"); 898 status = EXIT_PEER_AUTH_FAILED; 899} 900 901/* 902 * The peer has been successfully authenticated using `protocol'. 903 */ 904void 905auth_peer_success(unit, protocol, prot_flavor, name, namelen) 906 int unit, protocol, prot_flavor; 907 char *name; 908 int namelen; 909{ 910 int bit; 911 912 switch (protocol) { 913 case PPP_CHAP: 914 bit = CHAP_PEER; 915 switch (prot_flavor) { 916 case CHAP_MD5: 917 bit |= CHAP_MD5_PEER; 918 break; 919#ifdef CHAPMS 920 case CHAP_MICROSOFT: 921 bit |= CHAP_MS_PEER; 922 break; 923 case CHAP_MICROSOFT_V2: 924 bit |= CHAP_MS2_PEER; 925 break; 926#endif 927 } 928 break; 929 case PPP_PAP: 930 bit = PAP_PEER; 931 break; 932 case PPP_EAP: 933 bit = EAP_PEER; 934 break; 935 default: 936 warn("auth_peer_success: unknown protocol %x", protocol); 937 return; 938 } 939 940 /* 941 * Save the authenticated name of the peer for later. 942 */ 943 if (namelen > sizeof(peer_authname) - 1) 944 namelen = sizeof(peer_authname) - 1; 945 BCOPY(name, peer_authname, namelen); 946 peer_authname[namelen] = 0; 947 script_setenv("PEERNAME", peer_authname, 0); 948 949 /* Save the authentication method for later. */ 950 auth_done[unit] |= bit; 951 952 /* 953 * If there is no more authentication still to be done, 954 * proceed to the network (or callback) phase. 955 */ 956 if ((auth_pending[unit] &= ~bit) == 0) 957 network_phase(unit); 958} 959 960/* 961 * We have failed to authenticate ourselves to the peer using `protocol'. 962 */ 963void 964auth_withpeer_fail(unit, protocol) 965 int unit, protocol; 966{ 967 if (passwd_from_file) 968 BZERO(passwd, MAXSECRETLEN); 969 /* 970 * We've failed to authenticate ourselves to our peer. 971 * Some servers keep sending CHAP challenges, but there 972 * is no point in persisting without any way to get updated 973 * authentication secrets. 974 */ 975 lcp_close(unit, "Failed to authenticate ourselves to peer"); 976 status = EXIT_AUTH_TOPEER_FAILED; 977} 978 979/* 980 * We have successfully authenticated ourselves with the peer using `protocol'. 981 */ 982void 983auth_withpeer_success(unit, protocol, prot_flavor) 984 int unit, protocol, prot_flavor; 985{ 986 int bit; 987 988 switch (protocol) { 989 case PPP_CHAP: 990 bit = CHAP_WITHPEER; 991 switch (prot_flavor) { 992 case CHAP_MD5: 993 bit |= CHAP_MD5_WITHPEER; 994 break; 995#ifdef CHAPMS 996 case CHAP_MICROSOFT: 997 bit |= CHAP_MS_WITHPEER; 998 break; 999 case CHAP_MICROSOFT_V2: 1000 bit |= CHAP_MS2_WITHPEER; 1001 break; 1002#endif 1003 } 1004 break; 1005 case PPP_PAP: 1006 if (passwd_from_file) 1007 BZERO(passwd, MAXSECRETLEN); 1008 bit = PAP_WITHPEER; 1009 break; 1010 case PPP_EAP: 1011 bit = EAP_WITHPEER; 1012 break; 1013 default: 1014 warn("auth_withpeer_success: unknown protocol %x", protocol); 1015 bit = 0; 1016 } 1017 1018 /* Save the authentication method for later. */ 1019 auth_done[unit] |= bit; 1020 1021 /* 1022 * If there is no more authentication still being done, 1023 * proceed to the network (or callback) phase. 1024 */ 1025 if ((auth_pending[unit] &= ~bit) == 0) 1026 network_phase(unit); 1027} 1028 1029 1030/* 1031 * np_up - a network protocol has come up. 1032 */ 1033void 1034np_up(unit, proto) 1035 int unit, proto; 1036{ 1037 int tlim; 1038 1039 if (num_np_up == 0) { 1040 /* 1041 * At this point we consider that the link has come up successfully. 1042 */ 1043 status = EXIT_OK; 1044 unsuccess = 0; 1045 new_phase(PHASE_RUNNING); 1046 1047 if (idle_time_hook != 0) 1048 tlim = (*idle_time_hook)(NULL); 1049 else 1050 tlim = idle_time_limit; 1051 if (tlim > 0) 1052 TIMEOUT(check_idle, NULL, tlim); 1053 1054 /* 1055 * Set a timeout to close the connection once the maximum 1056 * connect time has expired. 1057 */ 1058 if (maxconnect > 0) 1059 TIMEOUT(connect_time_expired, 0, maxconnect); 1060 1061#ifdef MAXOCTETS 1062 if (maxoctets > 0) 1063 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout); 1064#endif 1065 1066 /* 1067 * Detach now, if the updetach option was given. 1068 */ 1069 if (updetach && !nodetach) 1070 detach(); 1071 } 1072 ++num_np_up; 1073} 1074 1075/* 1076 * np_down - a network protocol has gone down. 1077 */ 1078void 1079np_down(unit, proto) 1080 int unit, proto; 1081{ 1082 if (--num_np_up == 0) { 1083 UNTIMEOUT(check_idle, NULL); 1084 UNTIMEOUT(connect_time_expired, NULL); 1085#ifdef MAXOCTETS 1086 UNTIMEOUT(check_maxoctets, NULL); 1087#endif 1088 new_phase(PHASE_NETWORK); 1089 } 1090} 1091 1092/* 1093 * np_finished - a network protocol has finished using the link. 1094 */ 1095void 1096np_finished(unit, proto) 1097 int unit, proto; 1098{ 1099 if (--num_np_open <= 0) { 1100 /* no further use for the link: shut up shop. */ 1101 lcp_close(0, "No network protocols running"); 1102 } 1103} 1104 1105#ifdef MAXOCTETS 1106static void 1107check_maxoctets(arg) 1108 void *arg; 1109{ 1110 int diff; 1111 unsigned int used; 1112 1113 update_link_stats(ifunit); 1114 link_stats_valid=0; 1115 1116 switch(maxoctets_dir) { 1117 case PPP_OCTETS_DIRECTION_IN: 1118 used = link_stats.bytes_in; 1119 break; 1120 case PPP_OCTETS_DIRECTION_OUT: 1121 used = link_stats.bytes_out; 1122 break; 1123 case PPP_OCTETS_DIRECTION_MAXOVERAL: 1124 case PPP_OCTETS_DIRECTION_MAXSESSION: 1125 used = (link_stats.bytes_in > link_stats.bytes_out) ? link_stats.bytes_in : link_stats.bytes_out; 1126 break; 1127 default: 1128 used = link_stats.bytes_in+link_stats.bytes_out; 1129 break; 1130 } 1131 diff = maxoctets - used; 1132 if(diff < 0) { 1133 notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used); 1134 lcp_close(0, "Traffic limit"); 1135 need_holdoff = 0; 1136 status = EXIT_TRAFFIC_LIMIT; 1137 } else { 1138 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout); 1139 } 1140} 1141#endif 1142 1143/* 1144 * check_idle - check whether the link has been idle for long 1145 * enough that we can shut it down. 1146 */ 1147static void 1148check_idle(arg) 1149 void *arg; 1150{ 1151 struct ppp_idle idle; 1152 time_t itime; 1153 int tlim; 1154 1155 if (!get_idle_time(0, &idle)) 1156 return; 1157 if (idle_time_hook != 0) { 1158 tlim = idle_time_hook(&idle); 1159 } else { 1160 itime = MIN(idle.xmit_idle, idle.recv_idle); 1161 tlim = idle_time_limit - itime; 1162 } 1163 if (tlim <= 0) { 1164 /* link is idle: shut it down. */ 1165 notice("Terminating connection due to lack of activity."); 1166 lcp_close(0, "Link inactive"); 1167 need_holdoff = 0; 1168 status = EXIT_IDLE_TIMEOUT; 1169 } else { 1170 TIMEOUT(check_idle, NULL, tlim); 1171 } 1172} 1173 1174/* 1175 * connect_time_expired - log a message and close the connection. 1176 */ 1177static void 1178connect_time_expired(arg) 1179 void *arg; 1180{ 1181 info("Connect time expired"); 1182 status = EXIT_CONNECT_TIME; 1183 lcp_close(0, "Connect time expired"); /* Close connection */ 1184} 1185 1186/* 1187 * auth_check_options - called to check authentication options. 1188 */ 1189void 1190auth_check_options() 1191{ 1192 lcp_options *wo = &lcp_wantoptions[0]; 1193 int can_auth; 1194 int lacks_ip; 1195 1196 /* Default our_name to hostname, and user to our_name */ 1197 if (our_name[0] == 0 || usehostname) 1198 strlcpy(our_name, hostname, sizeof(our_name)); 1199 if (user[0] == 0) 1200 strlcpy(user, our_name, sizeof(user)); 1201 1202 /* 1203 * If we have a default route, require the peer to authenticate 1204 * unless the noauth option was given or the real user is root. 1205 */ 1206 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) { 1207 auth_required = 1; 1208 default_auth = 1; 1209 } 1210 1211 /* If we selected any CHAP flavors, we should probably negotiate it. :-) */ 1212 if (wo->chap_mdtype) 1213 wo->neg_chap = 1; 1214 1215 /* If authentication is required, ask peer for CHAP, PAP, or EAP. */ 1216 if (auth_required) { 1217 allow_any_ip = 0; 1218 if (!wo->neg_chap && !wo->neg_upap && !wo->neg_eap) { 1219 wo->neg_chap = chap_mdtype_all != MDTYPE_NONE; 1220 wo->chap_mdtype = chap_mdtype_all; 1221 wo->neg_upap = 1; 1222 wo->neg_eap = 1; 1223 } 1224 } else { 1225 wo->neg_chap = 0; 1226 wo->chap_mdtype = MDTYPE_NONE; 1227 wo->neg_upap = 0; 1228 wo->neg_eap = 0; 1229 } 1230 1231 /* 1232 * Check whether we have appropriate secrets to use 1233 * to authenticate the peer. Note that EAP can authenticate by way 1234 * of a CHAP-like exchanges as well as SRP. 1235 */ 1236 lacks_ip = 0; 1237 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip)); 1238 if (!can_auth && (wo->neg_chap || wo->neg_eap)) { 1239 can_auth = have_chap_secret((explicit_remote? remote_name: NULL), 1240 our_name, 1, &lacks_ip); 1241 } 1242 if (!can_auth && wo->neg_eap) { 1243 can_auth = have_srp_secret((explicit_remote? remote_name: NULL), 1244 our_name, 1, &lacks_ip); 1245 } 1246 1247 if (auth_required && !can_auth && noauth_addrs == NULL) { 1248 if (default_auth) { 1249 option_error( 1250"By default the remote system is required to authenticate itself"); 1251 option_error( 1252"(because this system has a default route to the internet)"); 1253 } else if (explicit_remote) 1254 option_error( 1255"The remote system (%s) is required to authenticate itself", 1256 remote_name); 1257 else 1258 option_error( 1259"The remote system is required to authenticate itself"); 1260 option_error( 1261"but I couldn't find any suitable secret (password) for it to use to do so."); 1262 if (lacks_ip) 1263 option_error( 1264"(None of the available passwords would let it use an IP address.)"); 1265 1266 exit(1); 1267 } 1268 1269 /* 1270 * Early check for remote number authorization. 1271 */ 1272 if (!auth_number()) { 1273 warn("calling number %q is not authorized", remote_number); 1274 exit(EXIT_CNID_AUTH_FAILED); 1275 } 1276} 1277 1278/* 1279 * auth_reset - called when LCP is starting negotiations to recheck 1280 * authentication options, i.e. whether we have appropriate secrets 1281 * to use for authenticating ourselves and/or the peer. 1282 */ 1283void 1284auth_reset(unit) 1285 int unit; 1286{ 1287 lcp_options *go = &lcp_gotoptions[unit]; 1288 lcp_options *ao = &lcp_allowoptions[unit]; 1289 int hadchap; 1290 1291 hadchap = -1; 1292 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL)); 1293 ao->neg_chap = (!refuse_chap || !refuse_mschap || !refuse_mschap_v2) 1294 && (passwd[0] != 0 || 1295 (hadchap = have_chap_secret(user, (explicit_remote? remote_name: 1296 NULL), 0, NULL))); 1297 ao->neg_eap = !refuse_eap && ( 1298 passwd[0] != 0 || 1299 (hadchap == 1 || (hadchap == -1 && have_chap_secret(user, 1300 (explicit_remote? remote_name: NULL), 0, NULL))) || 1301 have_srp_secret(user, (explicit_remote? remote_name: NULL), 0, NULL)); 1302 1303 hadchap = -1; 1304 if (go->neg_upap && !uselogin && !have_pap_secret(NULL)) 1305 go->neg_upap = 0; 1306 if (go->neg_chap) { 1307 if (!(hadchap = have_chap_secret((explicit_remote? remote_name: NULL), 1308 our_name, 1, NULL))) 1309 go->neg_chap = 0; 1310 } 1311 if (go->neg_eap && 1312 (hadchap == 0 || (hadchap == -1 && 1313 !have_chap_secret((explicit_remote? remote_name: NULL), our_name, 1314 1, NULL))) && 1315 !have_srp_secret((explicit_remote? remote_name: NULL), our_name, 1, 1316 NULL)) 1317 go->neg_eap = 0; 1318} 1319 1320 1321/* 1322 * check_passwd - Check the user name and passwd against the PAP secrets 1323 * file. If requested, also check against the system password database, 1324 * and login the user if OK. 1325 * 1326 * returns: 1327 * UPAP_AUTHNAK: Authentication failed. 1328 * UPAP_AUTHACK: Authentication succeeded. 1329 * In either case, msg points to an appropriate message. 1330 */ 1331int 1332check_passwd(unit, auser, userlen, apasswd, passwdlen, msg) 1333 int unit; 1334 char *auser; 1335 int userlen; 1336 char *apasswd; 1337 int passwdlen; 1338 char **msg; 1339{ 1340#if 1 1341 return UPAP_AUTHNAK; 1342#else 1343 int ret; 1344 char *filename; 1345 FILE *f; 1346 struct wordlist *addrs = NULL, *opts = NULL; 1347 char passwd[256], user[256]; 1348 char secret[MAXWORDLEN]; 1349 static int attempts = 0; 1350 1351 /* 1352 * Make copies of apasswd and auser, then null-terminate them. 1353 * If there are unprintable characters in the password, make 1354 * them visible. 1355 */ 1356 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd); 1357 slprintf(user, sizeof(user), "%.*v", userlen, auser); 1358 *msg = ""; 1359 1360 /* 1361 * Check if a plugin wants to handle this. 1362 */ 1363 if (pap_auth_hook) { 1364 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts); 1365 if (ret >= 0) { 1366 /* note: set_allowed_addrs() saves opts (but not addrs): 1367 don't free it! */ 1368 if (ret) 1369 set_allowed_addrs(unit, addrs, opts); 1370 else if (opts != 0) 1371 free_wordlist(opts); 1372 if (addrs != 0) 1373 free_wordlist(addrs); 1374 BZERO(passwd, sizeof(passwd)); 1375 return ret? UPAP_AUTHACK: UPAP_AUTHNAK; 1376 } 1377 } 1378 1379 /* 1380 * Open the file of pap secrets and scan for a suitable secret 1381 * for authenticating this user. 1382 */ 1383 filename = _PATH_UPAPFILE; 1384 addrs = opts = NULL; 1385 ret = UPAP_AUTHNAK; 1386 f = fopen(filename, "r"); 1387 if (f == NULL) { 1388 error("Can't open PAP password file %s: %m", filename); 1389 1390 } else { 1391 check_access(f, filename); 1392 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename, 0) < 0) { 1393 warn("no PAP secret found for %s", user); 1394 } else { 1395 /* 1396 * If the secret is "@login", it means to check 1397 * the password against the login database. 1398 */ 1399 int login_secret = strcmp(secret, "@login") == 0; 1400 ret = UPAP_AUTHACK; 1401 if (uselogin || login_secret) { 1402 /* login option or secret is @login */ 1403 if ((ret = plogin(user, passwd, msg)) == UPAP_AUTHACK) 1404 used_login = 1; 1405 } 1406 if (secret[0] != 0 && !login_secret) { 1407 /* password given in pap-secrets - must match */ 1408 if ((cryptpap || strcmp(passwd, secret) != 0) 1409 && strcmp(crypt(passwd, secret), secret) != 0) 1410 ret = UPAP_AUTHNAK; 1411 } 1412 } 1413 fclose(f); 1414 } 1415 1416 if (ret == UPAP_AUTHNAK) { 1417 if (**msg == 0) 1418 *msg = "Login incorrect"; 1419 /* 1420 * XXX can we ever get here more than once?? 1421 * Frustrate passwd stealer programs. 1422 * Allow 10 tries, but start backing off after 3 (stolen from login). 1423 * On 10'th, drop the connection. 1424 */ 1425 if (attempts++ >= 10) { 1426 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user); 1427 lcp_close(unit, "login failed"); 1428 } 1429 if (attempts > 3) 1430 sleep((u_int) (attempts - 3) * 5); 1431 if (opts != NULL) 1432 free_wordlist(opts); 1433 1434 } else { 1435 attempts = 0; /* Reset count */ 1436 if (**msg == 0) 1437 *msg = "Login ok"; 1438 set_allowed_addrs(unit, addrs, opts); 1439 } 1440 1441 if (addrs != NULL) 1442 free_wordlist(addrs); 1443 BZERO(passwd, sizeof(passwd)); 1444 BZERO(secret, sizeof(secret)); 1445 1446 return ret; 1447#endif 1448} 1449 1450/* 1451 * This function is needed for PAM. 1452 */ 1453 1454#ifdef USE_PAM 1455/* Static variables used to communicate between the conversation function 1456 * and the server_login function 1457 */ 1458static char *PAM_username; 1459static char *PAM_password; 1460static int PAM_error = 0; 1461static pam_handle_t *pamh = NULL; 1462 1463/* PAM conversation function 1464 * Here we assume (for now, at least) that echo on means login name, and 1465 * echo off means password. 1466 */ 1467 1468static int PAM_conv (int num_msg, 1469#ifndef SOL2 1470 const 1471#endif 1472 struct pam_message **msg, 1473 struct pam_response **resp, void *appdata_ptr) 1474{ 1475 int replies = 0; 1476 struct pam_response *reply = NULL; 1477 1478#define COPY_STRING(s) (s) ? strdup(s) : NULL 1479 1480 reply = malloc(sizeof(struct pam_response) * num_msg); 1481 if (!reply) return PAM_CONV_ERR; 1482 1483 for (replies = 0; replies < num_msg; replies++) { 1484 switch (msg[replies]->msg_style) { 1485 case PAM_PROMPT_ECHO_ON: 1486 reply[replies].resp_retcode = PAM_SUCCESS; 1487 reply[replies].resp = COPY_STRING(PAM_username); 1488 /* PAM frees resp */ 1489 break; 1490 case PAM_PROMPT_ECHO_OFF: 1491 reply[replies].resp_retcode = PAM_SUCCESS; 1492 reply[replies].resp = COPY_STRING(PAM_password); 1493 /* PAM frees resp */ 1494 break; 1495 case PAM_TEXT_INFO: 1496 /* fall through */ 1497 case PAM_ERROR_MSG: 1498 /* ignore it, but pam still wants a NULL response... */ 1499 reply[replies].resp_retcode = PAM_SUCCESS; 1500 reply[replies].resp = NULL; 1501 break; 1502 default: 1503 /* Must be an error of some sort... */ 1504 free (reply); 1505 PAM_error = 1; 1506 return PAM_CONV_ERR; 1507 } 1508 } 1509 *resp = reply; 1510 return PAM_SUCCESS; 1511} 1512 1513static struct pam_conv PAM_conversation = { 1514 &PAM_conv, 1515 NULL 1516}; 1517#endif /* USE_PAM */ 1518 1519/* 1520 * plogin - Check the user name and password against the system 1521 * password database, and login the user if OK. 1522 * 1523 * returns: 1524 * UPAP_AUTHNAK: Login failed. 1525 * UPAP_AUTHACK: Login succeeded. 1526 * In either case, msg points to an appropriate message. 1527 */ 1528 1529static int 1530plogin(user, passwd, msg) 1531 char *user; 1532 char *passwd; 1533 char **msg; 1534{ 1535 char *tty; 1536 1537#if 1 1538 return UPAP_AUTHNAK; 1539#else 1540#ifdef USE_PAM 1541 int pam_error; 1542 1543 pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh); 1544 if (pam_error != PAM_SUCCESS) { 1545 *msg = (char *) pam_strerror (pamh, pam_error); 1546 reopen_log(); 1547 return UPAP_AUTHNAK; 1548 } 1549 /* 1550 * Define the fields for the credential validation 1551 */ 1552 1553 PAM_username = user; 1554 PAM_password = passwd; 1555 PAM_error = 0; 1556 pam_set_item (pamh, PAM_TTY, devnam); /* this might be useful to some modules */ 1557 1558 /* 1559 * Validate the user 1560 */ 1561 pam_error = pam_authenticate (pamh, PAM_SILENT); 1562 if (pam_error == PAM_SUCCESS && !PAM_error) { 1563 pam_error = pam_acct_mgmt (pamh, PAM_SILENT); 1564 if (pam_error == PAM_SUCCESS) 1565 pam_error = pam_open_session (pamh, PAM_SILENT); 1566 } 1567 1568 *msg = (char *) pam_strerror (pamh, pam_error); 1569 1570 /* 1571 * Clean up the mess 1572 */ 1573 reopen_log(); /* apparently the PAM stuff does closelog() */ 1574 PAM_username = NULL; 1575 PAM_password = NULL; 1576 if (pam_error != PAM_SUCCESS) 1577 return UPAP_AUTHNAK; 1578#else /* #ifdef USE_PAM */ 1579 1580/* 1581 * Use the non-PAM methods directly 1582 */ 1583 1584#ifdef HAS_SHADOW 1585 struct spwd *spwd; 1586 struct spwd *getspnam(); 1587#endif 1588 struct passwd *pw = getpwnam(user); 1589 1590 endpwent(); 1591 if (pw == NULL) 1592 return (UPAP_AUTHNAK); 1593 1594#ifdef HAS_SHADOW 1595 spwd = getspnam(user); 1596 endspent(); 1597 if (spwd) { 1598 /* check the age of the password entry */ 1599 long now = time(NULL) / 86400L; 1600 1601 if ((spwd->sp_expire > 0 && now >= spwd->sp_expire) 1602 || ((spwd->sp_max >= 0 && spwd->sp_max < 10000) 1603 && spwd->sp_lstchg >= 0 1604 && now >= spwd->sp_lstchg + spwd->sp_max)) { 1605 warn("Password for %s has expired", user); 1606 return (UPAP_AUTHNAK); 1607 } 1608 pw->pw_passwd = spwd->sp_pwdp; 1609 } 1610#endif 1611 1612 /* 1613 * If no passwd, don't let them login. 1614 */ 1615 if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2 1616 || strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0) 1617 return (UPAP_AUTHNAK); 1618 1619#endif /* #ifdef USE_PAM */ 1620 1621 /* 1622 * Write a wtmp entry for this user. 1623 */ 1624 1625 tty = devnam; 1626 if (strncmp(tty, "/dev/", 5) == 0) 1627 tty += 5; 1628 logwtmp(tty, user, ifname); /* Add wtmp login entry */ 1629 1630#if defined(_PATH_LASTLOG) && !defined(USE_PAM) 1631 if (pw != (struct passwd *)NULL) { 1632 struct lastlog ll; 1633 int fd; 1634 1635 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 1636 (void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET); 1637 memset((void *)&ll, 0, sizeof(ll)); 1638 (void)time(&ll.ll_time); 1639 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 1640 (void)write(fd, (char *)&ll, sizeof(ll)); 1641 (void)close(fd); 1642 } 1643 } 1644#endif /* _PATH_LASTLOG and not USE_PAM */ 1645 1646 info("user %s logged in", user); 1647 logged_in = 1; 1648 1649 return (UPAP_AUTHACK); 1650#endif 1651} 1652 1653/* 1654 * plogout - Logout the user. 1655 */ 1656static void 1657plogout() 1658{ 1659#ifdef USE_PAM 1660 int pam_error; 1661 1662 if (pamh != NULL) { 1663 pam_error = pam_close_session (pamh, PAM_SILENT); 1664 pam_end (pamh, pam_error); 1665 pamh = NULL; 1666 } 1667 /* Apparently the pam stuff does closelog(). */ 1668 reopen_log(); 1669#else /* ! USE_PAM */ 1670 char *tty; 1671 1672 tty = devnam; 1673 if (strncmp(tty, "/dev/", 5) == 0) 1674 tty += 5; 1675 logwtmp(tty, "", ""); /* Wipe out utmp logout entry */ 1676#endif /* ! USE_PAM */ 1677 logged_in = 0; 1678} 1679 1680 1681/* 1682 * null_login - Check if a username of "" and a password of "" are 1683 * acceptable, and iff so, set the list of acceptable IP addresses 1684 * and return 1. 1685 */ 1686static int 1687null_login(unit) 1688 int unit; 1689{ 1690 char *filename; 1691 FILE *f; 1692 int i, ret; 1693 struct wordlist *addrs, *opts; 1694 char secret[MAXWORDLEN]; 1695 1696 /* 1697 * Check if a plugin wants to handle this. 1698 */ 1699 ret = -1; 1700 if (null_auth_hook) 1701 ret = (*null_auth_hook)(&addrs, &opts); 1702 1703 /* 1704 * Open the file of pap secrets and scan for a suitable secret. 1705 */ 1706 if (ret <= 0) { 1707 filename = _PATH_UPAPFILE; 1708 addrs = NULL; 1709 f = fopen(filename, "r"); 1710 if (f == NULL) 1711 return 0; 1712 check_access(f, filename); 1713 1714 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename, 0); 1715 ret = i >= 0 && secret[0] == 0; 1716 BZERO(secret, sizeof(secret)); 1717 fclose(f); 1718 } 1719 1720 if (ret) 1721 set_allowed_addrs(unit, addrs, opts); 1722 else if (opts != 0) 1723 free_wordlist(opts); 1724 if (addrs != 0) 1725 free_wordlist(addrs); 1726 1727 return ret; 1728} 1729 1730 1731/* 1732 * get_pap_passwd - get a password for authenticating ourselves with 1733 * our peer using PAP. Returns 1 on success, 0 if no suitable password 1734 * could be found. 1735 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null). 1736 */ 1737static int 1738get_pap_passwd(passwd) 1739 char *passwd; 1740{ 1741 char *filename; 1742 FILE *f; 1743 int ret; 1744 char secret[MAXWORDLEN]; 1745 1746 /* 1747 * Check whether a plugin wants to supply this. 1748 */ 1749 if (pap_passwd_hook) { 1750 ret = (*pap_passwd_hook)(user, passwd); 1751 if (ret >= 0) 1752 return ret; 1753 } 1754 1755 filename = _PATH_UPAPFILE; 1756 f = fopen(filename, "r"); 1757 if (f == NULL) 1758 return 0; 1759 check_access(f, filename); 1760 ret = scan_authfile(f, user, 1761 (remote_name[0]? remote_name: NULL), 1762 secret, NULL, NULL, filename, 0); 1763 fclose(f); 1764 if (ret < 0) 1765 return 0; 1766 if (passwd != NULL) 1767 strlcpy(passwd, secret, MAXSECRETLEN); 1768 BZERO(secret, sizeof(secret)); 1769 return 1; 1770} 1771 1772 1773/* 1774 * have_pap_secret - check whether we have a PAP file with any 1775 * secrets that we could possibly use for authenticating the peer. 1776 */ 1777static int 1778have_pap_secret(lacks_ipp) 1779 int *lacks_ipp; 1780{ 1781 FILE *f; 1782 int ret; 1783 char *filename; 1784 struct wordlist *addrs; 1785 1786 /* let the plugin decide, if there is one */ 1787 if (pap_check_hook) { 1788 ret = (*pap_check_hook)(); 1789 if (ret >= 0) 1790 return ret; 1791 } 1792 1793 filename = _PATH_UPAPFILE; 1794 f = fopen(filename, "r"); 1795 if (f == NULL) 1796 return 0; 1797 1798 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name, 1799 NULL, &addrs, NULL, filename, 0); 1800 fclose(f); 1801 if (ret >= 0 && !some_ip_ok(addrs)) { 1802 if (lacks_ipp != 0) 1803 *lacks_ipp = 1; 1804 ret = -1; 1805 } 1806 if (addrs != 0) 1807 free_wordlist(addrs); 1808 1809 return ret >= 0; 1810} 1811 1812 1813/* 1814 * have_chap_secret - check whether we have a CHAP file with a 1815 * secret that we could possibly use for authenticating `client' 1816 * on `server'. Either can be the null string, meaning we don't 1817 * know the identity yet. 1818 */ 1819static int 1820have_chap_secret(client, server, need_ip, lacks_ipp) 1821 char *client; 1822 char *server; 1823 int need_ip; 1824 int *lacks_ipp; 1825{ 1826 FILE *f; 1827 int ret; 1828 char *filename; 1829 struct wordlist *addrs; 1830 1831 if (chap_check_hook) { 1832 ret = (*chap_check_hook)(); 1833 if (ret >= 0) { 1834 return ret; 1835 } 1836 } 1837 1838 filename = _PATH_CHAPFILE; 1839 f = fopen(filename, "r"); 1840 if (f == NULL) 1841 return 0; 1842 1843 if (client != NULL && client[0] == 0) 1844 client = NULL; 1845 else if (server != NULL && server[0] == 0) 1846 server = NULL; 1847 1848 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0); 1849 fclose(f); 1850 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) { 1851 if (lacks_ipp != 0) 1852 *lacks_ipp = 1; 1853 ret = -1; 1854 } 1855 if (addrs != 0) 1856 free_wordlist(addrs); 1857 1858 return ret >= 0; 1859} 1860 1861 1862/* 1863 * have_srp_secret - check whether we have a SRP file with a 1864 * secret that we could possibly use for authenticating `client' 1865 * on `server'. Either can be the null string, meaning we don't 1866 * know the identity yet. 1867 */ 1868static int 1869have_srp_secret(client, server, need_ip, lacks_ipp) 1870 char *client; 1871 char *server; 1872 int need_ip; 1873 int *lacks_ipp; 1874{ 1875 FILE *f; 1876 int ret; 1877 char *filename; 1878 struct wordlist *addrs; 1879 1880 filename = _PATH_SRPFILE; 1881 f = fopen(filename, "r"); 1882 if (f == NULL) 1883 return 0; 1884 1885 if (client != NULL && client[0] == 0) 1886 client = NULL; 1887 else if (server != NULL && server[0] == 0) 1888 server = NULL; 1889 1890 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0); 1891 fclose(f); 1892 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) { 1893 if (lacks_ipp != 0) 1894 *lacks_ipp = 1; 1895 ret = -1; 1896 } 1897 if (addrs != 0) 1898 free_wordlist(addrs); 1899 1900 return ret >= 0; 1901} 1902 1903 1904/* 1905 * get_secret - open the CHAP secret file and return the secret 1906 * for authenticating the given client on the given server. 1907 * (We could be either client or server). 1908 */ 1909int 1910get_secret(unit, client, server, secret, secret_len, am_server) 1911 int unit; 1912 char *client; 1913 char *server; 1914 char *secret; 1915 int *secret_len; 1916 int am_server; 1917{ 1918 FILE *f; 1919 int ret, len; 1920 char *filename; 1921 struct wordlist *addrs, *opts; 1922 char secbuf[MAXWORDLEN]; 1923 1924 if (!am_server && passwd[0] != 0) { 1925 strlcpy(secbuf, passwd, sizeof(secbuf)); 1926 } else if (!am_server && chap_passwd_hook) { 1927 if ( (*chap_passwd_hook)(client, secbuf) < 0) { 1928 error("Unable to obtain CHAP password for %s on %s from plugin", 1929 client, server); 1930 return 0; 1931 } 1932 } else { 1933 filename = _PATH_CHAPFILE; 1934 addrs = NULL; 1935 secbuf[0] = 0; 1936 1937 f = fopen(filename, "r"); 1938 if (f == NULL) { 1939 error("Can't open chap secret file %s: %m", filename); 1940 return 0; 1941 } 1942 check_access(f, filename); 1943 1944 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename, 0); 1945 fclose(f); 1946 if (ret < 0) 1947 return 0; 1948 1949 if (am_server) 1950 set_allowed_addrs(unit, addrs, opts); 1951 else if (opts != 0) 1952 free_wordlist(opts); 1953 if (addrs != 0) 1954 free_wordlist(addrs); 1955 } 1956 1957 len = strlen(secbuf); 1958 if (len > MAXSECRETLEN) { 1959 error("Secret for %s on %s is too long", client, server); 1960 len = MAXSECRETLEN; 1961 } 1962 BCOPY(secbuf, secret, len); 1963 BZERO(secbuf, sizeof(secbuf)); 1964 *secret_len = len; 1965 1966 return 1; 1967} 1968 1969 1970/* 1971 * get_srp_secret - open the SRP secret file and return the secret 1972 * for authenticating the given client on the given server. 1973 * (We could be either client or server). 1974 */ 1975int 1976get_srp_secret(unit, client, server, secret, am_server) 1977 int unit; 1978 char *client; 1979 char *server; 1980 char *secret; 1981 int am_server; 1982{ 1983 FILE *fp; 1984 int ret; 1985 char *filename; 1986 struct wordlist *addrs, *opts; 1987 1988 if (!am_server && passwd[0] != '\0') { 1989 strlcpy(secret, passwd, MAXWORDLEN); 1990 } else { 1991 filename = _PATH_SRPFILE; 1992 addrs = NULL; 1993 1994 fp = fopen(filename, "r"); 1995 if (fp == NULL) { 1996 error("Can't open srp secret file %s: %m", filename); 1997 return 0; 1998 } 1999 check_access(fp, filename); 2000 2001 secret[0] = '\0'; 2002 ret = scan_authfile(fp, client, server, secret, &addrs, &opts, 2003 filename, am_server); 2004 fclose(fp); 2005 if (ret < 0) 2006 return 0; 2007 2008 if (am_server) 2009 set_allowed_addrs(unit, addrs, opts); 2010 else if (opts != NULL) 2011 free_wordlist(opts); 2012 if (addrs != NULL) 2013 free_wordlist(addrs); 2014 } 2015 2016 return 1; 2017} 2018 2019/* 2020 * set_allowed_addrs() - set the list of allowed addresses. 2021 * Also looks for `--' indicating options to apply for this peer 2022 * and leaves the following words in extra_options. 2023 */ 2024static void 2025set_allowed_addrs(unit, addrs, opts) 2026 int unit; 2027 struct wordlist *addrs; 2028 struct wordlist *opts; 2029{ 2030 int n; 2031 struct wordlist *ap, **plink; 2032 struct permitted_ip *ip; 2033 char *ptr_word, *ptr_mask; 2034 struct hostent *hp; 2035 struct netent *np; 2036 u_int32_t a, mask, ah, offset; 2037 struct ipcp_options *wo = &ipcp_wantoptions[unit]; 2038 u_int32_t suggested_ip = 0; 2039 2040 if (addresses[unit] != NULL) 2041 free(addresses[unit]); 2042 addresses[unit] = NULL; 2043 if (extra_options != NULL) 2044 free_wordlist(extra_options); 2045 extra_options = opts; 2046 2047 /* 2048 * Count the number of IP addresses given. 2049 */ 2050 n = wordlist_count(addrs) + wordlist_count(noauth_addrs); 2051 if (n == 0) 2052 return; 2053 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip)); 2054 if (ip == 0) 2055 return; 2056 2057 /* temporarily append the noauth_addrs list to addrs */ 2058 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next) 2059 ; 2060 *plink = noauth_addrs; 2061 2062 n = 0; 2063 for (ap = addrs; ap != NULL; ap = ap->next) { 2064 /* "-" means no addresses authorized, "*" means any address allowed */ 2065 ptr_word = ap->word; 2066 if (strcmp(ptr_word, "-") == 0) 2067 break; 2068 if (strcmp(ptr_word, "*") == 0) { 2069 ip[n].permit = 1; 2070 ip[n].base = ip[n].mask = 0; 2071 ++n; 2072 break; 2073 } 2074 2075 ip[n].permit = 1; 2076 if (*ptr_word == '!') { 2077 ip[n].permit = 0; 2078 ++ptr_word; 2079 } 2080 2081 mask = ~ (u_int32_t) 0; 2082 offset = 0; 2083 ptr_mask = strchr (ptr_word, '/'); 2084 if (ptr_mask != NULL) { 2085 int bit_count; 2086 char *endp; 2087 2088 bit_count = (int) strtol (ptr_mask+1, &endp, 10); 2089 if (bit_count <= 0 || bit_count > 32) { 2090 warn("invalid address length %v in auth. address list", 2091 ptr_mask+1); 2092 continue; 2093 } 2094 bit_count = 32 - bit_count; /* # bits in host part */ 2095 if (*endp == '+') { 2096 offset = ifunit + 1; 2097 ++endp; 2098 } 2099 if (*endp != 0) { 2100 warn("invalid address length syntax: %v", ptr_mask+1); 2101 continue; 2102 } 2103 *ptr_mask = '\0'; 2104 mask <<= bit_count; 2105 } 2106 2107 hp = gethostbyname(ptr_word); 2108 if (hp != NULL && hp->h_addrtype == AF_INET) { 2109 a = *(u_int32_t *)hp->h_addr; 2110 } else { 2111 np = getnetbyname (ptr_word); 2112 if (np != NULL && np->n_addrtype == AF_INET) { 2113 a = htonl ((u_int32_t)np->n_net); 2114 if (ptr_mask == NULL) { 2115 /* calculate appropriate mask for net */ 2116 ah = ntohl(a); 2117 if (IN_CLASSA(ah)) 2118 mask = IN_CLASSA_NET; 2119 else if (IN_CLASSB(ah)) 2120 mask = IN_CLASSB_NET; 2121 else if (IN_CLASSC(ah)) 2122 mask = IN_CLASSC_NET; 2123 } 2124 } else { 2125 a = inet_addr (ptr_word); 2126 } 2127 } 2128 2129 if (ptr_mask != NULL) 2130 *ptr_mask = '/'; 2131 2132 if (a == (u_int32_t)-1L) { 2133 warn("unknown host %s in auth. address list", ap->word); 2134 continue; 2135 } 2136 if (offset != 0) { 2137 if (offset >= ~mask) { 2138 warn("interface unit %d too large for subnet %v", 2139 ifunit, ptr_word); 2140 continue; 2141 } 2142 a = htonl((ntohl(a) & mask) + offset); 2143 mask = ~(u_int32_t)0; 2144 } 2145 ip[n].mask = htonl(mask); 2146 ip[n].base = a & ip[n].mask; 2147 ++n; 2148 if (~mask == 0 && suggested_ip == 0) 2149 suggested_ip = a; 2150 } 2151 *plink = NULL; 2152 2153 ip[n].permit = 0; /* make the last entry forbid all addresses */ 2154 ip[n].base = 0; /* to terminate the list */ 2155 ip[n].mask = 0; 2156 2157 addresses[unit] = ip; 2158 2159 /* 2160 * If the address given for the peer isn't authorized, or if 2161 * the user hasn't given one, AND there is an authorized address 2162 * which is a single host, then use that if we find one. 2163 */ 2164 if (suggested_ip != 0 2165 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) { 2166 wo->hisaddr = suggested_ip; 2167 /* 2168 * Do we insist on this address? No, if there are other 2169 * addresses authorized than the suggested one. 2170 */ 2171 if (n > 1) 2172 wo->accept_remote = 1; 2173 } 2174} 2175 2176/* 2177 * auth_ip_addr - check whether the peer is authorized to use 2178 * a given IP address. Returns 1 if authorized, 0 otherwise. 2179 */ 2180int 2181auth_ip_addr(unit, addr) 2182 int unit; 2183 u_int32_t addr; 2184{ 2185 int ok; 2186 2187 /* don't allow loopback or multicast address */ 2188 if (bad_ip_adrs(addr)) 2189 return 0; 2190 2191 if (allowed_address_hook) { 2192 ok = allowed_address_hook(addr); 2193 if (ok >= 0) return ok; 2194 } 2195 2196 if (addresses[unit] != NULL) { 2197 ok = ip_addr_check(addr, addresses[unit]); 2198 if (ok >= 0) 2199 return ok; 2200 } 2201 2202 if (auth_required) 2203 return 0; /* no addresses authorized */ 2204 return allow_any_ip || privileged || !have_route_to(addr); 2205} 2206 2207static int 2208ip_addr_check(addr, addrs) 2209 u_int32_t addr; 2210 struct permitted_ip *addrs; 2211{ 2212 for (; ; ++addrs) 2213 if ((addr & addrs->mask) == addrs->base) 2214 return addrs->permit; 2215} 2216 2217/* 2218 * bad_ip_adrs - return 1 if the IP address is one we don't want 2219 * to use, such as an address in the loopback net or a multicast address. 2220 * addr is in network byte order. 2221 */ 2222int 2223bad_ip_adrs(addr) 2224 u_int32_t addr; 2225{ 2226 addr = ntohl(addr); 2227 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET 2228 || IN_MULTICAST(addr) || IN_BADCLASS(addr); 2229} 2230 2231/* 2232 * some_ip_ok - check a wordlist to see if it authorizes any 2233 * IP address(es). 2234 */ 2235static int 2236some_ip_ok(addrs) 2237 struct wordlist *addrs; 2238{ 2239 for (; addrs != 0; addrs = addrs->next) { 2240 if (addrs->word[0] == '-') 2241 break; 2242 if (addrs->word[0] != '!') 2243 return 1; /* some IP address is allowed */ 2244 } 2245 return 0; 2246} 2247 2248/* 2249 * auth_number - check whether the remote number is allowed to connect. 2250 * Returns 1 if authorized, 0 otherwise. 2251 */ 2252int 2253auth_number() 2254{ 2255 struct wordlist *wp = permitted_numbers; 2256 int l; 2257 2258 /* Allow all if no authorization list. */ 2259 if (!wp) 2260 return 1; 2261 2262 /* Allow if we have a match in the authorization list. */ 2263 while (wp) { 2264 /* trailing '*' wildcard */ 2265 l = strlen(wp->word); 2266 if ((wp->word)[l - 1] == '*') 2267 l--; 2268 if (!strncasecmp(wp->word, remote_number, l)) 2269 return 1; 2270 wp = wp->next; 2271 } 2272 2273 return 0; 2274} 2275 2276/* 2277 * check_access - complain if a secret file has too-liberal permissions. 2278 */ 2279static void 2280check_access(f, filename) 2281 FILE *f; 2282 char *filename; 2283{ 2284 struct stat sbuf; 2285 2286 if (fstat(fileno(f), &sbuf) < 0) { 2287 warn("cannot stat secret file %s: %m", filename); 2288 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) { 2289 warn("Warning - secret file %s has world and/or group access", 2290 filename); 2291 } 2292} 2293 2294 2295/* 2296 * scan_authfile - Scan an authorization file for a secret suitable 2297 * for authenticating `client' on `server'. The return value is -1 2298 * if no secret is found, otherwise >= 0. The return value has 2299 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and 2300 * NONWILD_SERVER set if the secret didn't have "*" for the server. 2301 * Any following words on the line up to a "--" (i.e. address authorization 2302 * info) are placed in a wordlist and returned in *addrs. Any 2303 * following words (extra options) are placed in a wordlist and 2304 * returned in *opts. 2305 * We assume secret is NULL or points to MAXWORDLEN bytes of space. 2306 * Flags are non-zero if we need two colons in the secret in order to 2307 * match. 2308 */ 2309static int 2310scan_authfile(f, client, server, secret, addrs, opts, filename, flags) 2311 FILE *f; 2312 char *client; 2313 char *server; 2314 char *secret; 2315 struct wordlist **addrs; 2316 struct wordlist **opts; 2317 char *filename; 2318 int flags; 2319{ 2320 int newline, xxx; 2321 int got_flag, best_flag; 2322 FILE *sf; 2323 struct wordlist *ap, *addr_list, *alist, **app; 2324 char word[MAXWORDLEN]; 2325 char atfile[MAXWORDLEN]; 2326 char lsecret[MAXWORDLEN]; 2327 char *cp; 2328 2329 if (addrs != NULL) 2330 *addrs = NULL; 2331 if (opts != NULL) 2332 *opts = NULL; 2333 addr_list = NULL; 2334 if (!getword(f, word, &newline, filename)) 2335 return -1; /* file is empty??? */ 2336 newline = 1; 2337 best_flag = -1; 2338 for (;;) { 2339 /* 2340 * Skip until we find a word at the start of a line. 2341 */ 2342 while (!newline && getword(f, word, &newline, filename)) 2343 ; 2344 if (!newline) 2345 break; /* got to end of file */ 2346 2347 /* 2348 * Got a client - check if it's a match or a wildcard. 2349 */ 2350 got_flag = 0; 2351 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) { 2352 newline = 0; 2353 continue; 2354 } 2355 if (!ISWILD(word)) 2356 got_flag = NONWILD_CLIENT; 2357 2358 /* 2359 * Now get a server and check if it matches. 2360 */ 2361 if (!getword(f, word, &newline, filename)) 2362 break; 2363 if (newline) 2364 continue; 2365 if (!ISWILD(word)) { 2366 if (server != NULL && strcmp(word, server) != 0) 2367 continue; 2368 got_flag |= NONWILD_SERVER; 2369 } 2370 2371 /* 2372 * Got some sort of a match - see if it's better than what 2373 * we have already. 2374 */ 2375 if (got_flag <= best_flag) 2376 continue; 2377 2378 /* 2379 * Get the secret. 2380 */ 2381 if (!getword(f, word, &newline, filename)) 2382 break; 2383 if (newline) 2384 continue; 2385 2386 /* 2387 * SRP-SHA1 authenticator should never be reading secrets from 2388 * a file. (Authenticatee may, though.) 2389 */ 2390 if (flags && ((cp = strchr(word, ':')) == NULL || 2391 strchr(cp + 1, ':') == NULL)) 2392 continue; 2393 2394 if (secret != NULL) { 2395 /* 2396 * Special syntax: @/pathname means read secret from file. 2397 */ 2398 if (word[0] == '@' && word[1] == '/') { 2399 strlcpy(atfile, word+1, sizeof(atfile)); 2400 if ((sf = fopen(atfile, "r")) == NULL) { 2401 warn("can't open indirect secret file %s", atfile); 2402 continue; 2403 } 2404 check_access(sf, atfile); 2405 if (!getword(sf, word, &xxx, atfile)) { 2406 warn("no secret in indirect secret file %s", atfile); 2407 fclose(sf); 2408 continue; 2409 } 2410 fclose(sf); 2411 } 2412 strlcpy(lsecret, word, sizeof(lsecret)); 2413 } 2414 2415 /* 2416 * Now read address authorization info and make a wordlist. 2417 */ 2418 app = &alist; 2419 for (;;) { 2420 if (!getword(f, word, &newline, filename) || newline) 2421 break; 2422 ap = (struct wordlist *) 2423 malloc(sizeof(struct wordlist) + strlen(word) + 1); 2424 if (ap == NULL) 2425 novm("authorized addresses"); 2426 ap->word = (char *) (ap + 1); 2427 strcpy(ap->word, word); 2428 *app = ap; 2429 app = &ap->next; 2430 } 2431 *app = NULL; 2432 2433 /* 2434 * This is the best so far; remember it. 2435 */ 2436 best_flag = got_flag; 2437 if (addr_list) 2438 free_wordlist(addr_list); 2439 addr_list = alist; 2440 if (secret != NULL) 2441 strlcpy(secret, lsecret, MAXWORDLEN); 2442 2443 if (!newline) 2444 break; 2445 } 2446 2447 /* scan for a -- word indicating the start of options */ 2448 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next) 2449 if (strcmp(ap->word, "--") == 0) 2450 break; 2451 /* ap = start of options */ 2452 if (ap != NULL) { 2453 ap = ap->next; /* first option */ 2454 free(*app); /* free the "--" word */ 2455 *app = NULL; /* terminate addr list */ 2456 } 2457 if (opts != NULL) 2458 *opts = ap; 2459 else if (ap != NULL) 2460 free_wordlist(ap); 2461 if (addrs != NULL) 2462 *addrs = addr_list; 2463 else if (addr_list != NULL) 2464 free_wordlist(addr_list); 2465 2466 return best_flag; 2467} 2468 2469/* 2470 * wordlist_count - return the number of items in a wordlist 2471 */ 2472static int 2473wordlist_count(wp) 2474 struct wordlist *wp; 2475{ 2476 int n; 2477 2478 for (n = 0; wp != NULL; wp = wp->next) 2479 ++n; 2480 return n; 2481} 2482 2483/* 2484 * free_wordlist - release memory allocated for a wordlist. 2485 */ 2486static void 2487free_wordlist(wp) 2488 struct wordlist *wp; 2489{ 2490 struct wordlist *next; 2491 2492 while (wp != NULL) { 2493 next = wp->next; 2494 free(wp); 2495 wp = next; 2496 } 2497} 2498 2499/* 2500 * auth_script_done - called when the auth-up or auth-down script 2501 * has finished. 2502 */ 2503static void 2504auth_script_done(arg) 2505 void *arg; 2506{ 2507 auth_script_pid = 0; 2508 switch (auth_script_state) { 2509 case s_up: 2510 if (auth_state == s_down) { 2511 auth_script_state = s_down; 2512 auth_script(_PATH_AUTHDOWN); 2513 } 2514 break; 2515 case s_down: 2516 if (auth_state == s_up) { 2517 auth_script_state = s_up; 2518 auth_script(_PATH_AUTHUP); 2519 } 2520 break; 2521 } 2522} 2523 2524/* 2525 * auth_script - execute a script with arguments 2526 * interface-name peer-name real-user tty speed 2527 */ 2528static void 2529auth_script(script) 2530 char *script; 2531{ 2532 char strspeed[32]; 2533 struct passwd *pw; 2534 char struid[32]; 2535 char *user_name; 2536 char *argv[8]; 2537 2538 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL) 2539 user_name = pw->pw_name; 2540 else { 2541 slprintf(struid, sizeof(struid), "%d", getuid()); 2542 user_name = struid; 2543 } 2544 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate); 2545 2546 argv[0] = script; 2547 argv[1] = ifname; 2548 argv[2] = peer_authname; 2549 argv[3] = user_name; 2550 argv[4] = devnam; 2551 argv[5] = strspeed; 2552 argv[6] = NULL; 2553 2554 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL); 2555} 2556